The overall objective of this proposal is to provide a fast and reliable automated method for amplification-based genetic typing of point mutations and allelic single-base changes. The proposed method called ARCTM detection, is designed for analysis of highly polymorphic DNA targets that can be amplified by the polymerase chain reaction (PCR). The method can simultaneously type hundreds of nucleotide positions using the amplified products from a single PCR reaction. The ARCTM process relies on polymerase extension of allele-specific primer pairs that have been immobilized on a solid support. ARCTM detection will provide faster and more reliable typing results than allele-specific hybridization, with less technician labor, and should have broad applications in HLA typing, diagnosis of genetic disease, infectious disease diagnostics, forensics, genetic mapping and mutation analysis. In phase I, the feasibility of the proposed method will be tested by constructing a prototype, twelve-assay, multiplex ARC detector for typing all HLA-DQA1 alleles using a single amplification reaction. PROPOSED COMMERCIAL APPLICATIONS ARC TM detection will have broad applications in HLA typing, blood and plasma screening, genetic disease diagnosis, infectious disease diagnostics, cancer diagnostics, and DNA-based forensics. Our initial products will be HLA typing systems for the tissue-typing and forensic testing industries.